I have some boxwood handled multi hollowed Iyoroi chisels bought about 10 years ago from Japan Woodworker, pleased with these. Recent Devon bought Iyoroi seem less well made, the wider paring type particularly so, with a poorer looking weld - some traces of oxide? in the join. They were supplied very convex along the length, one eventually flattened by grinding out virtually all of the hollow, the other paring chisels (why did I not think of it earlier) carefully tapped out till as flat as possible and then ground flat.
As inspiring to good work as they may be, the expensive 'chisels as art' variety presumably add little to the ability to cut and hold an edge, if compared with a well made simpler style. The difficulty is to identify it! Has anyone tried the Matsumura chisels from Japan Woodworker, they got Fine Woodworking's gold star - but the competition did not include fancier brands